TOPEKA, Kan. (AP) — The Brown v. Board of Education National Historic site in Topeka will display a black doll used in a series of famous race studies to mark the anniversary of the U.S. Supreme Court ruling.

The case that toppled segregated education was decided 59 years ago Friday.

In the 1940s and 1950s, psychologists Kenneth and Mamie Clark presented children with a black doll and a white doll as part of social science experiments. The married black couple then asked the children which doll was the nicest, smartest and prettiest. Most chose the white doll.

The Clarks testified about the results in a South Carolina school desegregation case. That case was combined with other desegregation cases from Topeka, Virginia, Delaware and Washington, D.C. and were argued collectively before the Supreme Court.